Caustic Deluge

You open your mouth wide and exhale a deluge of acid into a 30-foot cone. Each creature in that area must make a Dexterity saving throw. On a failed save, a creature takes 6d6 acid damage and another 3d6 acid damage at the end of its next turn. On a successful save, a creature takes half the initial damage and no damage at the end of its next turn.

A nonmagical object that isn't being worn or carried takes both the initial and secondary damage if it's in the spell's area.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the initial damage increases by 1d6 for each slot level above 3rd.